Easy to use nitrogen shock adapter for filling shock absorbers has a special no loss air chuck valve so no pressure is lost during filling. Features a built in pressure gauge that allows the shock to be filled within 10 pounds of accuracy. Great for use on King, Fox, Sway-A-Way, Bilstein, or Marvin Shaw Shocks. Uses a 11/16 wrench to tighten it to the shock's schrader valve.